Airplane.



C. J. LAKE.

AIRPLANE.

APPLICATION F1151) 1AN.16.1918.

1,279,127. Patentedsept-1z1918,

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CHRISTOPHER J'. LAKE, OF BRIDGEPORT, CNNECTICUT.

AIRPLANE.

Specification of Letters Patent. Patented Sept. 17, 1918.

Application filed January 16, 1918. Serial No. 212,019.

. To all whom t may concern:

Be it known `that I, CHRISTOPHR J. LAKE, a citizen of the United States,and resldent lof Bridgeport, in the county of Fairfield vcend or descendwhile maintaining a fairly constant flying angle. Further my inventionis directed to the provision of a low center of gravity, as a factor ofstability in an airplane having control means whereby vertical movementis accomplishedwithout appreciable variation in the flying angle.

In other words, my purpose is to so coordinate the factors of controlfor vertical movement and for longitudinal stability that the airplanemay maintain approximately the same attitude, when either ascending ordescending, as when in horizontal flight.

Other features and advantages of my said invention will hereinafterappear.

In the drawing Figure 1 is'a side elevation of an airplane embodying myimprovements.

Fig. 2 is a plan view thereof, the main supporting unit being partlybroken-away.

Fig. 3 is a side Vviewwit the auxiliary aerofoils adjusted for ascent.Fi 4 is a similar view .with the auxiliary aero oils adjusted'for'descent Fig. 5 is ai correspondlng view showing the auxiliaryaerofoils as variably adjustedl for ascent, and

Fig. 6 yis a detail of a form of control mechanism forthe auxiliaryaerofoils.

In the example of my invention illustratedin this application, I haveshown it, for the-,sake of simplicity, as employed with a single mainsupporting unit, which is here represented as a monoplane, whereas I donot intend to limit myself either to the number or character o f mainsupporting units.

Thus, in the figures let 1 indicate the body portion or frame of theairplane, and 2-the main supporting unit, which is connected to the bodyportion as by struts 3. Auxiliary supporting aerofoils 4 and 5 aremounted upon the body portion, respectively fore and aft thereof, beingpivoted in bearings 6 and 7 respectively, as by the transverse pivots 8.

It should 'be particularly noted that the main supporting unit 2 isdisposed above the center of gravity, this arrangement predicating thecondition that the main supporting aerofoil is in fixed relation to thebody portion with a predetermined set angle of incidence.

The aerofoils 4 and 5 mayhave cables 9,

9a and 10, 10a respectively, which are shown as engaging, respectively,with control levers 11, 12, which are here shown as pivoted,respectively at 13 and 14, to a common, fixed support 15, to each swinglongitudinally, and are engaged with each other, as by a connector 16,whereby the movement of said levers 11,12 may be concurrent.

It will be noted that the cable 9 extendsl from a spur 9b projectingfrom the upper surface of aerofoil 4, to a point of engagement with thelever 11 above its fulcrum; the cable 9a extending from a spur 9c thatprojects from the under surface of'said aerofoil to a .point ofengagement with said lever below its fulcrum. Similarly, cables 10 and10a connect the Aaerofoil 5 with lever 12 through the respectiveagencies of spurs 10b and 10?. Thus, to incline both aerofoils 4 and 5-upwardly, the levers are swung in manner to draw cable 9 rearwardly andcable 10a forwardly; while,to incline-said aerofoils downwardly, thelevers are swung oppositely, to therebydraw cable 9a rearwardly andcable 10 forwardly.

The connector, as 16, may be of a charac-- ter t0 permit the levers 11,12 to assume varyingdegrees of angularity relatively to each other, tothus affect the relation between the angles of the fore and aftaerofoil? when it is desirable to vary .those angles. Thus, consideringany condition such as a shift in weight thatA changesl the center ofgravity in the machine, affecting its longitudinal equilibrium, thisfmaybe easily compensated for by: increasing the attacking angle oftheaerofoil at that end of the airplane toward which there is an accessionof weight, whereby the trim of the airplane enables it to maintainapproximately its normal horizontal flying attitude.

In Fig. 5 I have shown an airplane'wherein a forward 'shift of weightmay be considered to have occurred, in which instance the fore'aerofoil4 has been given a greater angle of attack, for increased support, and

the aft aerofoil has been given a relatively smaller angle of incidence,afording less support, to thus equilibrize the machine.

As here shown, the connector 16 comprises" a screw having right and leftthreads which, respectively, work in threaded bearings therefor in thelevers 11, 12.

In the operation of the controls, the pilot moves thel connected leversforwardly orbackwardly, for which purpose,v he may grasp the wheel 17;whereby, when it is necessary to vary the relative angles of aerofoils 4and 5, they pilot may give the necessary turn to said wheel toactuatethe screw connector 16.

Obviously, the combined motions of the screw and levers will producevariable relative movements of the aerofoils, embracing a wide range ofdifference in angularity between said aerofoils. y

In an airplane having controls of the character set forth, whereby theairplane may be vcaused to ascend and descend, as it were on an evenkeel, it is particularly desirable to .provide a low center of gravity,which preferably should. be in the vertical line of the center ofpressure for the main supporting unit, a's at 18. By this means thefactors of control and weight cordinate with the supporting pressure tobalance the airplane in a normally horizontal attitude, in normalforward flight, as -well asin vertical variations thereof.

' of incidence,"of auxiliary fore and aftaero- Y Iplanelto maintain anapproxlniately hori zontal 'attitudeiin ascent andv descent.

2. The combination in an airplane having a main 'supporting unit with aixed angle foils equal spaces from, and in a horizontal plane passingsubstantially through, the center of gravity of said airplane, and means.for simultaneously varying the angles of said aerofoils in the samedirection vto thereby enable the airplane to maintain Lavare? anapproximately horizontal attitude in ascent and descent.

3. Thev combination in an airplane having a main supporting unit with afixed angle of incidence, of auxiliary fore and aft aerofoils equalspaces from, and in a horizontal plane passing substantially through,the center of gravity of said airplane, and means for differentiallyvarying the angles of -said aerofoils in the same direction to therebyenable the airplane to maintain an approximately horizontal attitude inascent and descent.

4:. The combination, in an airplane, having a main supporting unit, witha fixed angle of incidence, disposed above the center of gravity of saidairplane, of lauxiliary aerofoils mounted respectively equal spaces foreand aft of, and in a horizontal plane passing substantially through, thecenter of gravity of said airplane, and means for varying the angles ofsaidV aerofoils in the same direction to thereby enable the airplane to.maintain anapproximately horizontal attitude in ascent and descent.

5. The combination, inian airplane, having a main supportingv unit, witha fixed angle ofincidence, disposed above the center of gravity of saidairplane, of auxiliary aerofoils mounted respectively equal spaces foreand aft of, anda in a horizontal plane passing substantially through,the center of gravity of -said airplane, and means for simultaneouslyvaryingk the angles of said aerofoils in the same direction to therebyenable the airplane to maintain an approximately horizontal attitude iny,ascent anddescent. v

6. The combination, in an airplane, hav,- ing a main supporting unit,with a fixed angle of incidence, disposed above the center of gravity ofsaid airplane, of auxiliary aerofoils mounted respectively equal spacesfore and aft of, and in a horizontal plane passing substantiallythrough, the center of 'gravity of said airplane, and means fordifferentially varying the. angles of said areofoils in the same',dlirectlon to thereby enable the airplane to maintain an approximatelyhorizontal attitude in ascent and descent.

Signed at the borough of Manhattan in the city, county and State of NewYork this 10th. day of January A. D. 1918.

CHRISTOPHER J. LAKE. Witnesses:

F. W. BARKER, MoNTAGUn PALMER.

